高寒区混凝土坝温控防裂施工技术及工程应用

Construction Technology and Engineering Application of Temperature Control and Crack Prevention for Concrete Dams in High Cold Region

温控是大体积混凝土施工的重点难点技术之一,高寒区由于年均气温低、昼夜温差大等特殊自然气候,混凝土面临的冬季防冻、温差控制等问题更为复杂。文章以不同龄期混凝土自约束拉应力和外约束拉应力满足抗拉极限为理论基础,结合施工控制措施,提出了高寒区混凝土温控防裂施工技术,并以扎敦水利枢纽混凝土坝为实例进行应用。监测成果显示:大坝温控效果好,满足混凝土绝热温升等要求,可有效控制温度裂缝发生。该技术可为高寒区混凝土坝温控防裂施工提供借鉴。

Temperature control is one of the key and difficult technologies for mass concrete construction. Concrete is faced with more complex problems such as winter freeze protection, temperature difference control, etc. due to the low average annual temperature, large temperature difference between day and night as well as other special natural climate in the high cold region. In the paper, self-restrained tensile stress and external restrained tensile stress of concrete at different ages meet the ultimate tensile strength. Construction control measures are combined based on the theory. Construction technology of temperature control and crack prevention for concrete in the cold region is proposed. Concrete dam of Zhadun Water Control Project is adopted as an example for application. The monitoring results show that the temperature control effect of the dam is excellent, which meets the requirements of concrete adiabatic temperature rise and can effectively control temperature cracks. The technology can be used as reference in the construction of temperature control and crack prevention for concrete dams in high cold regions.